Updated /help, added auth can challenge /bc users 

Updated /help to show all about /faq, added the ability for auth to challenge users in /bc after popular request.
Allowing auth to challenge users in /bc

Added auth check so they can challenge users in /bc.
Added permission to be able to challenge /bc

Added permission for auths to be able to challenge users in /bc
Merge pull request #148 from Joimer/patch-2

Updated /help, added permission so auths can challenge through /bc
Fix naming conventions on challengeblock code
Refactored getTarget and validTargetLoc.